Externally mounted in-line exhaust gas valve

ABSTRACT

A valve assembly for an exhaust system of a vehicle. The valve assembly includes a first housing, a second housing, a valve flap and a spring. The first housing defines an inlet, an outlet, and an exhaust gas passageway in fluid communication with the inlet and the outlet. The second housing is attached to the first housing and defines a compartment. The valve flap is rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is allowed. The spring is disposed in the compartment and out of the exhaust gas passageway. The spring engages the valve flap to bias the valve flap toward the first position.

FIELD

The present disclosure relates to an externally mounted in-line exhaustgas valve.

BACKGROUND

This section provides background information related to the presentdisclosure and is not necessarily prior art.

Many vehicle exhaust systems use active and/or passive valve assembliesto alter the characteristics of exhaust flow through a conduit as theexhaust pressure increases due to increasing engine speed. Active valvescarry the increased expense of requiring a specific actuating element,such as a solenoid. By contrast, passive valves generally include aspring biased valve flap and utilize the pressure of the exhaust flow inthe conduit to actuate (i.e., open) the valve. Although passive valvesare less expensive, traditional passive valves can be difficult topackage and are susceptible to vibration related noise and excessivevalve flutter caused by flowrate fluctuations in the engine's exhaustflow (i.e., exhaust pulsation). Such valves can present vibration andnoise problems due to resonance of the valve flap and biasing spring. Asa result, there remains a need for improved passive valves.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

In one form, the present disclosure provides a valve assembly for anexhaust system of a vehicle. The valve assembly includes a firsthousing, a second housing, a valve flap and a spring. The first housingdefines an inlet, an outlet, and a longitudinally extending exhaust gaspassageway in fluid communication with the inlet and the outlet. Thesecond housing is coupled to the first housing and defines acompartment. The valve flap is rotatable between a first positionrestricting exhaust gas flow through the exhaust gas passageway, and asecond position whereat exhaust gas flow through the exhaust gaspassageway is less restricted. The spring is disposed in the compartmentand outside of the exhaust gas passageway. The spring urging the valveflap toward the first position.

In some configurations of the valve assembly of the above paragraph, thespring extends in the longitudinal direction.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the first housing includes an anchor extending intothe compartment. The spring has a first end attached to the anchor and asecond end attached to an end section of the valve flap positioned inthe compartment.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the end section has a first portion and a secondportion. The second portion extends away from the first portion at anangle.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the angle is between 100 degrees and 175 degrees.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the end section has a first portion and a secondportion. The second portion extending toward a pivot axis of the valveflap. The second end of the spring being attached to the second portionto reduce a torque magnitude required to maintain the valve flap in thesecond position.

In some configurations of the valve assembly of any one or more of theabove paragraphs, a torque magnitude required to move the valve flapfrom the first position is greater than a torque magnitude required tomaintain the valve flap at the second position.

In another form, the present disclosure provides a valve assembly for anexhaust system of a vehicle. The valve assembly includes a firsthousing, a heat shield, a second housing, a valve flap and a spring. Thefirst housing defines an inlet, an outlet, and an exhaust gas passagewayin fluid communication with the inlet and the outlet. The heat shield iscoupled to the first housing. The second housing is coupled to the firsthousing and cooperates with the heat shield to form a substantiallyenclosed compartment. The valve flap is rotatable between a firstposition restricting exhaust gas flow through the exhaust gaspassageway, and a second position whereat exhaust gas flow through theexhaust gas passageway is less restricted. The spring is disposed in thecompartment and out of the exhaust gas passageway. The spring isdisposed in the compartment and outside of the exhaust gas passageway.The spring biases the valve flap toward the first position. The springis movable between first and second locations. The spring being in thefirst location when the valve flap is in the first position and in thesecond location when the valve flap is in the second position. Thespring being further away from the first housing when in the firstlocation than when in the second location.

In some configurations of the valve assembly of the above paragraphs,the first housing includes an anchor extending into the compartment. Thespring has a first end attached to the anchor and a second end attachedto an end section of the valve flap positioned in the compartment.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the heat shield defines a cutout. The end section ofthe valve flap extends through the cutout and into the compartment.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the second housing includes an outer wall having afirst portion and a second portion. The first portion being spaced apartfrom the first housing a greater distance than the second portionthereby accommodating the spring as it moves between the first andsecond locations.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the outer wall extends parallel to the spring when thespring is at the first location.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the heat shield defines first and second openings. Thefirst opening accommodates the first end of the spring and the secondopening accommodates the second end of the spring when the spring movesbetween the first and second locations.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the valve flap covers the first opening and the secondopening when in the second position, thereby reducing backpressure.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the heat shield includes an indentation that extendsat least partially into the exhaust gas passageway. The spring isaccommodated within a trough formed by the indentation when the springis in the second location to prevent the spring from contacting the heatshield.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the valve flap abuts against the indentation when inthe second position to prevent further rotation of the valve flap awayfrom the exhaust gas passageway.

In some configurations of the valve assembly of any one or more of theabove paragraphs, wherein the valve assembly further includes a springdamper attached to the spring and configured to dampen vibrations of thespring.

In yet another form, the present disclosure provides a valve assemblyfor an exhaust system of a vehicle. The valve assembly includes a firsthousing, a second housing, a valve flap and a spring. The first housingdefines an inlet, an outlet, and an exhaust gas passageway in fluidcommunication with the inlet and the outlet. The second housing iscoupled to the first housing to define a compartment. The valve flap isrotatable between a first position restricting exhaust gas flow throughthe exhaust gas passageway, and a second position whereat exhaust gasflow through the exhaust gas passageway is less restricted. The valveflap includes an end section disposed within the compartment and a bodysection disposed in the exhaust gas passageway. The spring is disposedin the compartment and outside of the exhaust gas passageway. The springbiases the valve flap toward the first position. The spring is attachedto the end section and defines a moment arm to which the spring appliesa torque about the axis. The moment arm decreases as the valve flaprotates from the first position toward the second position.

In some configurations of the valve assembly of the above paragraph, thevalve assembly further comprising a spring damper coupled to the springand configured to dampen vibrations of the spring.

In some configurations of the valve assembly of any one or more of theabove paragraphs, the spring extends in the longitudinal direction.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a schematic representation of an engine and an exhaust systemhaving a valve assembly according to the principles of the presentdisclosure;

FIG. 2 is a perspective view of the valve assembly of FIG. 1;

FIG. 3 is a front view of the valve assembly;

FIG. 4 is a back view of the valve assembly;

FIG. 5 is an exploded perspective view of the valve assembly;

FIG. 6 is another exploded perspective view of the valve assembly;

FIG. 7 is a cross-sectional view of the valve assembly with a valve flapassembly in an open position;

FIG. 8 is a cross-sectional view of the valve assembly with the valveflap assembly in a closed position;

FIG. 9 is another cross-sectional view of the valve assembly with thevalve flap assembly in the open position;

FIG. 10 is a perspective view of the valve assembly with a portion of asecond housing cutaway; and

FIG. 11 is an enlarged cross-sectional view of a portion of the valveassembly with the second housing omitted and includes a free-bodydiagram of the force system acting on the valve flap of the valveassembly.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

As shown in FIG. 1, an engine 12 and an exhaust system 14 are shownschematically. The engine 12 may be an internal combustion engineassociated with a vehicle (not shown), for example. Exhaust gas may bedischarged from the engine 12 and may subsequently flow through theexhaust system 14. The exhaust system 14 may include an exhaust pipe 16,a catalytic converter 17, an exhaust gas valve or valve assembly 18, amuffler 19 and a tailpipe 20. Exhaust gas discharged from the engine 12may flow through the exhaust pipe 16, the catalytic converter 17, valveassembly 18, the muffler 19, and may exit through the tailpipe 20. Thevalve assembly 18 may be disposed upstream of the muffler 19 (e.g.,between the catalytic converter 17 and the muffler 19). In someconfigurations, the valve assembly 18 may be dispose downstream of themuffler 19.

With reference to FIGS. 2-10, the valve assembly 18 may include a firsthousing assembly 22, a second housing assembly 24 (FIGS. 2-9) and avalve flap assembly 26 (FIGS. 5-9). As shown in FIGS. 7 and 8, the firsthousing assembly 22 may define an inlet 30, an outlet 32 and a fluidpassageway 34 extending in a longitudinal direction of the first housingassembly 22 and between the inlet 30 and the outlet 32. The inlet 30 mayhave a diameter D₁ that is wider than a diameter of an inlet connectingpipe 36 (FIG. 2) attached to the first housing assembly 22 at the inlet30 so that the exhaust gas flowing from the inlet connecting pipe 36into the first housing assembly 22 has a smooth flow transition. Theoutlet 32 may have a diameter D₂ that is smaller than a diameter of anoutlet connecting pipe 38 (FIG. 2) attached to the first housingassembly 22 at the outlet 32 so that the exhaust gas flowing from thefirst housing assembly 22 into the outlet connecting pipe 38 has asmooth flow transition. This minimizes noise of the exhaust gas that isgenerated by turbulence. The diameter D₁ of the inlet 30 is also widerthan the diameter D₂ of the outlet 32.

The first housing assembly 22 may include a monolithic first or uppershell 40 and a second or lower shell 42. In some configurations, thefirst and second shells 40, 42 may be side shells that are symmetric toeach other about plane A. The first and second shells 40, 42 may beformed by a stamping process. The first shell 40 may have a generallysemi-circular or “U” cross-sectional shape and may define an opening 44(FIGS. 5 and 6) at a top side 46 thereof. As shown in FIGS. 5 and 6,opposing sidewalls or ears 48 may be integrally formed with the firstshell 40 and may extend upwardly from respective sides 50 of the firstshell 40. Each sidewall 48 may include a trunnion 51 that is positionedabove and out of the fluid passageway 34. The trunnions 51 may beopposed to each other and may each define an aperture or cavity 52extending at least partially therethrough.

A bushing 53 may be made of a metallic material and may be press-fitinto a respective trunnion 51. In some configurations, the bushing 53may be made of a wire-mesh material and may be attached to therespective trunnion 51 by other suitable means (e.g., mechanicalattachments, adhesives, etc.). Each bushing 53 may include acylindrically-shaped central portion 54 and a peripheral portion 55 thatextends around and radially outwardly from a periphery of the centralportion 54. As shown in FIG. 9, the central portion 54 may be disposedwithin the aperture 52 of the respective trunnion 51 such that an outercylindrical surface 57 of the central portion 54 contacts an innercylindrical surface 58 of the aperture 52. The peripheral portion 55 maybe disposed between the sidewall 48 and the second housing assembly 24and may have an inner surface 59 that contacts an outer surface 56 ofthe sidewall 48. As shown in FIGS. 5-8, an anchor feature 60 may beintegrally formed with the first shell 40 and may extend upwardly fromthe top side 46 of the first shell 40. The anchor feature 60 may also bepositioned above and out of the fluid passageway 34.

The second shell 42 may have a generally semi-circular or “U”cross-sectional shape and may be attached to the first shell 40 suchthat the first and second shells 40, 42 cooperate to define the inlet30, the outlet 32 and the fluid passageway 34. The first and secondshells 40, 42 may also be attached (e.g., welded) to each other at ajoint 61. That is, as best shown in FIG. 9, the second shell 42 mayinclude a first end portion or edge 62 that at least partially overlapsa first end portion or edge 64 of the first shell 40 at the joint 61.The second shell 42 may also include a second end portion or edge 65having a flange 71 that is attached to (e.g., welded) a flange 69extending from a second end portion or edge 70 of the first shell 40 atthe joint 61.

A heat shield or cover plate 72 may be made of a metallic material andmay be attached (e.g., welded) to an outer surface 73 of the first shell40 at the top side 46 thereof such that the shield 72 substantiallycovers the opening 44. Stated another way, a periphery of the shield 72may be welded to the outer surface 73 of the first shell 40 at the topside 46 thereof. As shown in FIGS. 5 and 6, the shield 72 may have avalve-flap section 74, a shaft section 76 and an end section 78. Thevalve-flap section 74 may be planar and may have a slot 79 formedtherein that receives or accommodates the anchor feature 60. Anindentation 80 may be formed in the valve-flap section 74 and at leastpartially in the shaft section 76. The indentation 80 extends at leastpartially into the fluid passageway 34 (FIGS. 7 and 8) and may includean aperture 81.

The shaft section 76 may be positioned between the valve-flap section 74and the end section 78 and may have a generally semi-circular or “U”cross-sectional shape. As shown in FIG. 9, the shaft section 76 may alsobe positioned between the sidewalls 48 extending upwardly from the firstshell 40 and may cover or overlap a portion of the trunnions 51 and thebushings 53. The shaft section 76 may also define a cutout 82 that thevalve flap assembly 26 extends through. The end section 78 may be planarand may have an aperture 84.

As shown in FIGS. 2-4 and 7-9, the second housing assembly or doghouse24 may be disposed on the first shell 40 at the top side 46 thereof. Thesecond housing assembly 24 may house the valve flap assembly 26, theears 48, the trunnions 51, the bushings 53, the anchor feature 60 andthe shield 72. The second housing assembly 24, the shield 72 and theupper shell 40 may cooperate to form a substantially enclosedcompartment 85. The second housing assembly 24 may be sealingly engagedto the first shell 40 to prevent fluid in the fluid passageway 34 fromleaking out. The second housing assembly 24 may be symmetrical about aplane A dividing the fluid passageway 34 in half (FIG. 9).

The second housing assembly 24 may include a first shell 86 and a secondshell 88. The first and second shells 86, 88 may be formed by a stampingprocess and may be made of a metallic material (e.g., steel). The firstand second shells 86, 88 may be arranged in a side by side fashion andmay be attached (e.g., welded) to each other at a joint 89 (FIGS. 2 and9) that extends a length of the second housing assembly 24. As shown inFIGS. 5 and 6, each of the first and second shells 86, 88 may include acurved flange 90 extending from a front end 92 and a curved flange 93extending from a rear end 94. The flanges 90, 93 of the shells 86, 88are formed for welding the shells 86, 88 to the upper shell 40, therebycreating a seal between the shells 86, 88 and the upper shell 40. Thefirst shell 86 may include a first end portion or edge 96 of side 98that is attached (e.g., welded) to the side 50 of the upper shell 40,thereby creating a seal between the shell 86 and the upper shell 40.Similarly, the second shell 88 may include a first end portion or edge100 of side 102 that is attached (e.g., welded) to the other side 50 ofthe upper shell 40, thereby creating a seal between the shell 88 and theupper shell 40. The second shell 88 may also include a second endportion 104 that overlaps a second end portion 106 of the first shell 86at the joint 89. Stated another way, an inner surface 108 of the secondshell 88 is welded to an outer surface 110 of the first shell 86 at thejoint 89, thereby creating a seal between the shells 86, 88 (FIG. 9).

The first shell 86 may include a bushing receptacle 112 integrallyformed therewith at the side 98 and the second shell 88 may include abushing receptacle 113 integrally formed therewith at the side 100 andaligned with the bushing receptacle 112. Prior to attaching the shells86, 88 to the upper shell 40, each shell 86, 88 may be attached to(e.g., pressed onto) a respective bushing 53 such that an outer surface114 of the peripheral portion 55 contacts a circular-shaped wall 116 ofthe respective bushing receptacle 112, 113 (FIG. 9). In this way, thebushings 53 may be in a heat transfer relationship with the secondhousing assembly 24 and may transfer heat thereto. In someconfigurations, the shells 86, 88 may be attached to the bushings 53 byother suitable means (e.g., mechanical attachments).

The valve flap assembly 26 may include a valve shaft 118, a spring 120and a monolithic valve flap 122. As shown in FIG. 9, the valve shaft 118may be housed within the second housing assembly 24 (i.e., out of thefluid passageway 34) and may extend transverse (i.e., perpendicularrelative to the longitudinal direction of the first housing assembly 22)to the fluid passageway 34. The shaft section 76 of the shield 72 mayaccommodate the valve shaft 118 (i.e., the shaft 118 may extend througha space 123 defined by the shaft section 76). The valve shaft 118 mayhave an axis 124 that is positioned above the first housing assembly 22and out of the fluid passageway 34 (FIG. 9). The valve shaft 118 and thetrunnions 51 may be coaxially aligned. The valve shaft 118 may extend atleast partially through openings 126 of each bushing 53 so that thebushings 53 are disposed on opposing ends 128 of the valve shaft 118,thereby rotatably supporting the valve shaft 118.

As shown in FIGS. 7 and 8, the spring 120 may be housed within thesecond housing assembly 24 and may extend in a longitudinal direction ofthe second housing assembly 24. The spring 120 may include a firstconnecting element 130, a coil 132 and a second connecting element 134.The first connecting element 130 may extend from an end of the coil 132and may have a hook-shape that is engaged with the anchor feature 60(i.e., the first connecting element 130 is disposed in an opening 138 ofthe anchor feature 60). The second connecting element 134 may extendfrom another end of the coil 132 and may also have a hook-shape that isengaged with the valve flap 122. In this way, the valve flap 122 isrotationally biased toward a first position (i.e., a closed position).

The valve flap 122 may be made of a metallic material (e.g., steel) andmay extend through the cutout 82 of the shaft section 76. The valve flap122 may be fixed for rotation with the valve shaft 118 and may berotatable about the axis 124 of the valve shaft 118 between the firstposition (FIG. 8) whereat fluid is restricted from flowing through thefluid passageway 34 and a second position (FIG. 7; an open position)whereat fluid is allowed to flow through the fluid passageway 34. Thespring 120 may move between first and second states or locations whenthe valve flap 122 rotates between the first and second positions. Thatis, the spring 120 may be in the first state when the valve flap 122 isin the first position, and may be in the second state when the valveflap 122 is in the second position. The spring 120 may be a furtherdistance from the first housing assembly 22 (and the shield 72) when inthe first state (i.e., the valve flap 122 is in the first position) thenwhen in the second state (i.e., the valve flap 122 is in the secondposition). A distance between the top side 46 of the upper shell 40 anda top side 142 of the shells 86, 88 may increase from the rear end 94 ofthe shells 86, 88 to the front end 92 of the shells 86, 88. In this way,the movement of the spring 120 (and the valve flap 122) may beaccommodated for (i.e., the spring 120 and the valve flap 122 areprevented from contacting the second housing assembly 24 at all times).

As shown in FIG. 7, when the valve flap 122 is moved to the secondposition, a recess or trough 144 formed by the indentation 80 of theshield 72 accommodates the coil 132 of the spring 120, the aperture 81of the shield 72 accommodates the first connecting element 130 of thespring 120, and the aperture 84 of the shield 72 accommodates the secondconnecting element 134 of the spring 120. In this way, the spring 120 isprevented from contacting the shield 72, which, in turn, prevents heattransferred to the shield 72 (i.e., from the exhaust gas and the firsthousing assembly 22) from being transferred to the spring 120.Accordingly, the spring 120 is able to operate at cooler temperatures.

The valve flap 122 may have a plate section 146, a shaft section 148 andan arm or end section 150. With reference to FIGS. 3-8, the platesection 146 may be planar and may be disposed within the first housingassembly 22 (FIGS. 3, 4, 7 and 8). The plate section 146 may block orprevent fluid flow through the fluid passageway 34 when the valve flap122 is the first position and may allow fluid flow through the fluidpassageway 34 when the valve flap 122 is in the second position. Atriangular-shaped indentation 152 may be formed in the plate section 146and at least partially in the shaft section 148.

The shaft section 148 may be positioned between the plate section 146and the end section 150 and may have a generally “U” cross-sectionalshape. As shown in FIGS. 7 and 8, the shaft section 148 may be partiallydisposed within the first housing assembly 22 and partially disposedwithin the second housing assembly 24. The shaft section 148 may beattached (e.g., welded) to a diametrical surface 156 of the valve shaft118 so that the valve flap 122 is rotationally fixed to the valve shaft118. As shown in FIG. 9, the shaft section 148 of the valve flap 122 andthe shaft section 76 of the shield 72 may cooperate to act as a shroudor cover to the valve shaft 118 along a length thereof. The shaftsection 148 may include protrusions 157 extending outwardly fromopposing ends thereof. The protrusions 157 may be configured to contactthe bushings 53, thereby restricting movement of the valve shaft 118(and the valve flap 122) in an axial direction.

As shown in FIGS. 7 and 8, the end section 150 may extend from the shaftsection 148 and through the cutout 82 formed in the shaft section 76 ofthe shield 72. In this way, the end section 150 is positioned within thesecond housing assembly 24. The end section 150 may have a curve or bendtherein. The end section 150 may include a first portion 158 and asecond portion 160 extending at an angle α relative to the first portion158. The angle α may be between 90 and 179 degrees. The second portion160 of the end section 150 has an aperture 164 formed therein. Thesecond connecting element 134 is engaged with the second portion 160 ofthe end section 150 (i.e., the second connecting element is disposed inthe aperture 164 of the second portion 160).

When a pressure drop (differential between the inlet connecting pipe 36and the outlet connecting pipe 38) exceeds a preload of the spring 120,the valve flap 122 moves from the first position toward the secondposition. By the second connecting element 134 being engaged with thesecond portion 160 of the end section 150 as opposed to the firstportion 158 (or along a plane 163 of the first portion 158), the torquerequired to maintain the valve flap 122 in the second position (or movethe valve flap 122 toward the second position when the valve flap 122 ismoved from the first position) is reduced, which reduces backpressure.

For example, as shown in FIG. 11, the second connecting element 134being engaged with the second portion 160 of the end section 150 whenthe valve flap 122 is in the second position creates a moment arm L_(o)(i.e., perpendicular distance between the pivot axis 124 and the forceF_(o)) that is smaller than a moment arm L_(c) (i.e., perpendiculardistance between the pivot axis 124 and the force F_(c)) when the valveflap 122 is in the first position. Accordingly, the moment arm L_(o) isminimized by moving the spring attachment point closer to pivot axis 124when the valve flap 122 is in the second position (i.e., open position).In this way, a torque (torque_(o)=L_(o)F_(o)) required to maintain thevalve flap 122 in the second position is smaller than a torque(torque_(c)=L_(c)F_(c)) required to move the valve flap 122 from thefirst position. It should be understood that although the spring 120extends slightly longer in the second location than in the firstlocation, the force F_(o) is minimally greater than the force F_(c) andthus the torque at both locations being impacted more by respectivemoments arms L_(o), L_(c). As depicted in FIG. 11, L_(c) issubstantially greater than L_(o).

A generally semi-circular shaped first pad 166 may be attached to thevalve flap 122 and may include a first portion 167 a and a secondportion 167 b that is movable relative to the first portion 167 a. Thefirst portion 167 a may include a first recess 175 a defining a firstsurface 177 a and the second portion 167 b may include a second recess175 b defining a second surface 177 b. The second portion 167 b may beangled relative to the first portion 167 a when the valve flap 122 isremoved from the first position (FIG. 7) and may be aligned with thefirst portion 167 a when the valve flap 122 is in the first position(FIG. 8; the first and second surfaces 177 a, 177 b are coplanar).

A portion of the plate section 146 is received in the first recess 175 aand contacts the first surface 177 a when the valve flap 122 is removedfrom the first position (i.e., a first surface 168 of the plate section146 contacts the first surface 177 a). A portion of the plate section146 is received in the first and second recesses 175 a, 175 b andcontacts the first and second surfaces 177 a, 177 b when the valve flap122 is in the first position (i.e., the first surface 168 of the platesection 146 contacts the first and second surfaces 177 a, 177 b). Acurved periphery 169 of the second portion 167 b contacts an innersurface 170 of the lower shell 42 when the valve flap 122 is moved tothe first position, which causes the second portion 167 b to move intoalignment with the first portion 167 a and absorb energy of the valveflap 122 and the spring 120, thereby reducing noise generated. Thecurved periphery 169 may extend past or cover a curved periphery 171 ofthe plate section 146. The first pad 166 may be made of a deformablewire-mesh material or any other suitable material that further reducesnoise as the first pad 166 contacts or engages the inner surface 170 ofthe lower shell 42.

As shown in FIGS. 7 and 8, a U-shaped unitary mass damper 172 may bepositioned on a second surface 174 of the plate section 146 that isopposite the first surface 168. The mass damper 172 may be made of ahigh-density material (density≥10 g/cm³) that is able to withstand thetemperature of the exhaust gas. For example, the mass damper 172 may bemade of a tungsten carbide material. The mass damper 172 has a higherdensity then that of the valve flap 122. The mass damper 172 is formedby a molding and/or machining process. A curved periphery 173 of themass damper 172 is aligned with the curved periphery 171 of the platesection 146 (i.e., the curved periphery of the mass damper 172 does notextend past the curved periphery of the plate section 146). The massdamper 172 and the second surface 174 may face the outlet 32 of thehousing assembly 22 when the valve flap 122 is in the first position,and the first pad 166 and the first surface 168 may face the inlet 30 ofthe housing assembly 22 when the valve flap 122 is in the firstposition. When the valve flap 122 is in the first position, the massdamper 172 prevents the valve flap 122 from moving and making noiseswhen exhaust pulsations are experienced.

The mass damper 172 may include end portions 176 and an intermediateportion 178 disposed between the end portions 176. Each end portion 176may include an aperture 180 that is in alignment with respectiveapertures 181, 182 of the plate section 146 and the first pad 166,respectively. A plurality of fasteners 179 (e.g., rivets, bolts, screws)may extend through the apertures 180, 181, 182 of the end portion 176,the plate section 146 and the first pad 166, respectively, therebyattaching the first pad 166, the mass damper 172 and the valve flap 122to each other. As shown in FIG. 5, an outer surface 184 of the firstportion 167 a of the first pad 166 may include annular-shaped recesses186 formed therein and around the apertures 181. In this way, a head 187of each fastener 179 may be received in the recess 186 (FIGS. 3 and 9)such that the head 187 is flush with the outer surface 184. Thisprovides for less flow disruption when the valve flap 122 is in thesecond position.

As shown in FIGS. 4 and 6, the intermediate portion 178 of the massdamper 172 has a thickness that is thicker than a thickness of the endportions 176. The intermediate portion 178 has a groove 185 formed in aplanar surface 191 thereof.

With reference to FIGS. 4, 7 and 8, a generally triangular-shaped secondpad 188 may be received within a recess 190 formed by the indentation152 in the plate section 146 and may be attached to (e.g., spot welded)the plate section 146 of the valve flap 122 via grooves 193. In thisway, when the valve flap 122 is in the second position, the second pad188 engages the indentation 80 of the shield 72 to prevent the valveflap 122 from further rotation while allowing for minimum intrusion ofthe valve flap 122 in the fluid passageway 34. Also, when the valve flap122 is in the second position, the recess 190 of the mass damper 172accommodates the indentation 80 of the shield 72, which, in turn,prevents heat transferred to the shield 72 from being transferred to themass damper 172 (i.e., prevents the heat shield 72 from contacting themass damper 172).

When the valve flap 122 is in the second position, the mass damper 172(or the plate section 146 of the valve flap 122) may at least partiallyblock the aperture 81 of the heat shield 72 and the arm 150 may at leastpartially block the aperture 84 of the heat shield 72. This, in turn,reduces backpressure of the apparatus 18. When the valve flap is in thefirst position, a portion of the exhaust gas flowing in the inlet 30 mayflow through the aperture 84, the compartment 85, the aperture 81 andout the outlet 32. Stated another way, the inlet 30, the aperture 84,the compartment 85, the aperture 81 and the outlet 32 may form a bypasspassageway 192 for exhaust gas flowing through the apparatus 18 when thevalve flap 122 is in the first position. The second pad 188 may be madeof a deformable wire-mesh material or any other suitable material thatreduces noise as the second pad 188 contacts or engages the indentation80 of the shield 72.

With continued reference to FIGS. 1-11, assembly of the valve assembly18 will now be described. First, each bushing 53 is pressed in therespective trunnion 51. Next, the valve shaft 118 is inserted throughthe openings 126 of each bushing 53 so that the bushings 53 are disposedon opposing ends 128 of the valve shaft 118.

Next, the first pad 166, the second pad 188 and the mass damper 172 areattached to the valve flap 122. That is, the first pad 166 and the massdamper 172 are attached to the valve flap 122 via fasteners 179 and thesecond pad 188 is welded to the valve flap 122. The valve flap 122 isthen welded to the valve shaft 118 and centered.

Next, the shield 72 is welded to the upper shell 40. Next, the uppershell 40 is welded to the lower shell 42. The spring 120 is thenattached to the anchor feature 60 and the arm 150 of the valve flap 122.Finally, the shells 66, 68 are welded to each other and then to theupper shell 40.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

What is claimed is:
 1. A valve assembly for an exhaust system of avehicle, the valve assembly comprising: a first housing defining aninlet, an outlet, and a longitudinally extending exhaust gas passagewayin fluid communication with the inlet and the outlet; a second housingcoupled to the first housing and at least partially defining acompartment; a valve flap rotatable between a first position restrictingexhaust gas flow through the exhaust gas passageway, and a secondposition whereat exhaust gas flow through the exhaust gas passageway isless restricted; and a spring disposed in the compartment and outside ofthe exhaust gas passageway, the spring urging the valve flap toward thefirst position.
 2. The valve assembly of claim 1, wherein the springextends in the longitudinal direction.
 3. The valve assembly of claim 1,wherein the first housing includes an anchor extending into thecompartment, and wherein the spring has a first end attached to theanchor and a second end attached to an end section of the valve flappositioned in the compartment.
 4. The valve assembly of claim 3, whereinthe end section has a first portion and a second portion, and whereinthe second portion extends away from the first portion at an angle. 5.The valve assembly of claim 4, wherein the angle is between 100 degreesand 175 degrees.
 6. The valve assembly of claim 3, wherein the endsection has a first portion and a second portion, the second portionextending toward a pivot axis of the valve flap, the second end of thespring being attached to the second portion to reduce a torque magnituderequired to maintain the valve flap in the second position.
 7. The valveassembly of claim 3, wherein a torque magnitude required to move thevalve flap from the first position is greater than a torque magnituderequired to maintain the valve flap at the second position.
 8. A valveassembly for an exhaust system of a vehicle, the valve assemblycomprising: a first housing defining an inlet, an outlet, and alongitudinally extending exhaust gas passageway in fluid communicationwith the inlet and the outlet; a heat shield coupled to the firsthousing; a second housing coupled to the first housing and cooperatingwith the heat shield and the first housing to define a substantiallyenclosed compartment; a valve flap rotatable between a first positionrestricting exhaust gas flow through the exhaust gas passageway, and asecond position whereat exhaust gas flow through the exhaust gaspassageway is less restricted; and a spring disposed in the compartmentand outside of the exhaust gas passageway, the spring biasing the valveflap toward the first position, wherein the spring is movable betweenfirst and second locations, the spring being in the first location whenthe valve flap is in the first position and in the second location whenthe valve flap is in the second position, the spring being further awayfrom the first housing when in the first location than when in thesecond location.
 9. The valve assembly of claim 8, wherein the firsthousing includes an anchor extending into the compartment, and whereinthe spring has a first end coupled to the anchor and a second endcoupled to an end section of the valve flap positioned in thecompartment.
 10. The valve assembly of claim 9, wherein the heat shielddefines a cutout, the end section of the valve flap extending throughthe cutout and into the compartment.
 11. The valve assembly of claim 8,wherein the second housing includes an outer wall having a first portionand a second portion, the first portion being spaced apart from thefirst housing a greater distance than the second portion therebyaccommodating the spring as it moves between the first and secondlocations.
 12. The valve assembly of claim 11, wherein the outer wallextends parallel to the spring when the spring is at the first location.13. The valve assembly of claim 8, wherein the heat shield defines firstand second openings, and wherein the first opening accommodates thefirst end of the spring and the second opening accommodates the secondend of the spring when the spring moves between the first and secondlocations.
 14. The valve assembly of claim 13, wherein the valve flapcovers the first opening and the second opening when in the secondposition, thereby reducing backpressure.
 15. The valve assembly of claim8, wherein the heat shield includes an indentation that extends at leastpartially into the exhaust gas passageway, and wherein the spring isaccommodated within a trough formed by the indentation when the springis in the second location to prevent the spring from contacting the heatshield.
 16. The valve assembly of claim 15, wherein the valve flap abutsagainst the indentation when in the second position to prevent furtherrotation of the valve flap away from the exhaust gas passageway.
 17. Avalve assembly for an exhaust system of a vehicle, the valve assemblycomprising: a first housing defining an inlet, an outlet, and anlongitudinally extending exhaust gas passageway in fluid communicationwith the inlet and the outlet; a second housing coupled to the firsthousing to define a compartment; a valve flap rotatable about an axisbetween a first position restricting exhaust gas flow through theexhaust gas passageway and a second position whereat exhaust gas flowthrough the exhaust gas passageway is less restricted, the valve flapincluding an end section disposed within the compartment and a bodysection disposed in the exhaust gas passageway; and a spring disposed inthe compartment and outside of the exhaust gas passageway, the springbiasing the valve flap toward the first position, wherein the spring isattached to the end section and defines a moment arm to which the springapplies a torque about the axis, wherein the moment arm decreases as thevalve flap rotates from the first position toward the second position.18. The valve assembly of claim 17, wherein the spring extends in thelongitudinal direction.
 19. The valve assembly of claim 17, wherein thefirst housing includes an anchor extending into the compartment, andwherein the spring is also coupled to the anchor.
 20. The valve assemblyof claim 19, wherein a torque magnitude required to move the valve flapfrom the first position is greater than a torque magnitude required tomaintain the valve flap at the second position.